Shockwave cosmology is a non-standard cosmology proposed by

Joel Smoller Joel Alan Smoller (2 January 1936 – 27 September 2017) was an American mathematician. Joel Smoller was born in Brooklyn on 2 January 1936 to parents Benjamin, a taxicab driver, and Olga, who died when he was young. Smoller attended New York Univ ...

and Blake Temple in 2003. In this model, the “

big bang The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models based on the Big Bang concept explain a broad range of phenomena, including th ...

” is an explosion inside a

black hole A black hole is a massive, compact astronomical object so dense that its gravity prevents anything from escaping, even light. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. Th ...

, producing the expanding volume of space and matter that includes the

observable universe The observable universe is a Ball (mathematics), spherical region of the universe consisting of all matter that can be observation, observed from Earth; the electromagnetic radiation from these astronomical object, objects has had time to reach t ...

Integration with general relativity

Smoller and Temple integrate

shock waves In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...

into Einstein's

general relativity General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the differential geometry, geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of grav ...

. This produces a

universe The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from s ...

that "looks essentially identical to the aftermath of the big bang" according to

cosmologists Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe, the cosmos. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', with the meaning of "a speaking of the wor ...

Barnes and Lewis. They explain that Smoller and Temple's version is distinguished from the big bang only by there being a shockwave at the leading edge of an explosion – one that, for Smoller and Temple's model, must be beyond the observable universe. However, Barnes and Lewis do not support shockwave cosmology because they see it as not testable; they point out that there is no explosion in the standard theory of the Big Bang.

Current and future state of the universe

From Smoller and Temple's calculations, we are still inside an expanding

. The configuration of 'flat' spacetime (see Minkowski space) inside a black hole, also occurs during the moments of the formation of a black hole from a collapsing star. Eventually, according to shockwave cosmology, the

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

of our expanding volume of space and matter will fall in

density Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...

as it expands. At some point, the

event horizon In astrophysics, an event horizon is a boundary beyond which events cannot affect an outside observer. Wolfgang Rindler coined the term in the 1950s. In 1784, John Michell proposed that gravity can be strong enough in the vicinity of massive c ...

of the black hole will cease to be. An outside observer will then see it appear as a

white hole In general relativity, a white hole is a hypothetical region of spacetime and Gravitational singularity, singularity that cannot be entered from the outside, although energy, matter, light and information can escape from it. In this sense, it is ...

. The matter would then continue to expand.

Alternative to dark energy

In related work, Smoller, Temple, and Vogler propose that this

shockwave In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...

may have resulted in our part of the universe having a lower density than that surrounding it, causing the accelerated expansion normally attributed to

dark energy In physical cosmology and astronomy, dark energy is a proposed form of energy that affects the universe on the largest scales. Its primary effect is to drive the accelerating expansion of the universe. It also slows the rate of structure format ...

. They also propose that this related theory could be tested: a universe with dark energy should give a figure for the cubic correction to

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and increase in frequency and e ...

versus

luminosity Luminosity is an absolute measure of radiated electromagnetic radiation, electromagnetic energy per unit time, and is synonymous with the radiant power emitted by a light-emitting object. In astronomy, luminosity is the total amount of electroma ...

C = −0.180 at a = a whereas for Smoller, Temple, and Vogler's alternative C should be positive rather than negative. They give a more precise calculation for their wave model alternative as: the cubic correction to redshift versus luminosity at a = a is C = 0.359.

Comparison with standard cosmology

Although shockwave cosmology produces a universe that "looks essentially identical to the aftermath of the big bang", cosmologists consider that it needs further development before it could be considered as a more advantageous model than the big bang theory (or standard model) in explaining the universe. In particular, and especially for the proposed alternative to dark energy, it would need to explain

big bang nucleosynthesis In physical cosmology, Big Bang nucleosynthesis (also known as primordial nucleosynthesis, and abbreviated as BBN) is a model for the production of light nuclei, deuterium, 3He, 4He, 7Li, between 0.01s and 200s in the lifetime of the universe ...

, the quantitative details of the

microwave background The cosmic microwave background (CMB, CMBR), or relic radiation, is microwave radiation that fills all space in the observable universe. With a standard optical telescope, the background space between stars and galaxies is almost completely dar ...

anisotropies, the

Lyman-alpha forest In astronomical spectroscopy, the Lyman-alpha forest is a series of absorption lines in the spectra of distant galaxies and quasars arising from the Lyman-alpha electron transition of the neutral hydrogen atom. As the light travels through mult ...

, and galaxy surveys.

References

{{reflist Physics Astronomy